Uncaught Exceptions:
- TypeError: null is not an object (evaluating 'this.dataGrid._popover') (at ResourceTimelineDataGridNode.js:424:82)
? @ ResourceTimelineDataGridNode.js:424:82
* STEPS TO REPRODUCE
1. In Web Inspector, open Network tab
2. Open http://webkit.org/
3. Hover over the timing bar at the right side of the content view to show the timing information popover.
4. Quickly click on the Clear Network Items icon.